Tharisa Minerals’ Tharisa mine has kicked off its new underground mining era with its inaugural blast on Tuesday.

With the depletion of the mine’s openpit resources expected by around 2034, the platinum group metals mine, on the western limb of the Bushveld Complex, in North West province, is strategically transitioning to underground mining, said Tharisa CEO Phoevos Pouroulis.

“It was always envisaged that we would transition to underground mining, and we are now at that point in time,” he told Mining Weekly during a visit to the mine to witness the first blast.

With a completed definitive feasibility study and board approval behind it, the mine has been preparing over the past 18 months to ensure the high wall was safe and to establish the access points for the inaugural blast.

“It is a milestone event for us as it signals the future of our operations. We have had this long life with the resource in the openpit, but by going underground now, we unlock at least 60 years of mine life.”

The underground progression comprises two decline developments that will eventually meet to deliver an aggregate 510 000 t a month.

Tharisa has started with the Apollo portal access on the west side of the openpit operation, ramping up over the next three years to a steady state of 255 000 t a month.

“As we achieve that steady state, we will start with the Orion east side portal development, where we will then join the two workings of the underground,” he explained, adding that the transition to fully underground operations will be completed by 2034.

The east and west operations will be mirrored equally at output of 255 000 t each, equating to over 6.2-million tonnes on an annual basis, which provides the mine some headroom in terms of its processing nameplate capacity of 5.6-million tonnes and opening the optionality of increasing its processing capacity.

Through its mining contractor, Cementation Africa, plans are underway to upskill and transition the mine’s current operators from openpit to underground.

Further, the fully-equipped smart mine, with technologies deployed through a technical partnership with Dwyka labs, was established with the ability to leverage new technology as it evolved.